Positive Feedback ISSUE 66
march/april 2013

 

 

The Audio Circular 3 - Singing Beautifully: The Bel Canto DAC 2.5 Control Center and uLink USB Converter
by Gary Beard

 

bel canto 2.5

My interest in the exploding USB audio market is very high and I have been trying to gain some experience and perspective on USB DACs. While light on USB audio experience, I am not a computer audio newbie; I started my first computer based system way back in 2005 with the purchase of a Squeezebox 2. I love the convenience of the Squeezebox, but it can be a bit contrary and stubborn at times. For the last few years I have been using the SB2's digital output to drive a Bel Canto DAC 2. The 2 has been one of my favorite audio purchases and if there were an Audio Value Hall of Fame, it would certainly belong in the DAC gallery. Having such an appreciation for the DAC 2, I was delighted to have the opportunity to experience the Bel Canto e.One Series DAC 2.5 Control Center as well as the uLink USB Converter. Both rolled into my listening room in November 2012. First introduced in 2010, the earth-friendly DAC 2.5's elegant yet simple outer skin sneakily hides a high level of engineering that turns the 2.5 into a digital audio nerve center. The newly introduced uLink USB converter was an unexpected addition to my Bel Canto experience. Whereas the 2.5 has a built-in 24 bit/96kHz USB input which requires no additional drivers, the uLink is an Asynchronous USB converter and 24 bit/ 192kHz capable with downloadable software drivers. While ultimately I might prefer a single unit rather than two boxes and associated cables; the low noise, galvanically isolated uLink allows the flexibility to connect to any DAC with an S/PDIF input.

The DAC 2.5 is an incredibly versatile music making machine. By virtue of its stereo analog RCA input, the 2.5 can be used as an analog preamp. It has a 24-bit digital volume control and a slew of connection options. In addition to the on-board USB, a multitude of 24-bit/192kHz capable inputs—Toslink, AES/EBU, S/PDIF—share the rear panel with XLR and RCA analog outputs. There is also a 1/4" front mounted Headphone jack for the dedicated headphone amp. I used them all with the exception of the Toslink input and XLR output. All input selections and DAC functions are displayed on the front LED panel and accessed from the very cool front mounted push/turn control "wheel" or the included remote control.

The manual will dazzle with the DAC 2.5's capabilities, but there are a number of relatively minor ones that really caught my fancy. Press the mute button once for 50% and twice for 100% mute and yet again to restore to full volume. This was a nice touch when I wanted to quickly turn down the music to talk with my spouse without interrupting Stairway to Heaven. The volume of each input is individually controlled and remembers your last setting, thus eliminating accidental, ear-bleeding mistakes when changing inputs. And I really love the .5db increments of the digital volume control. As someone who has had a fair number of stepped volume controls over the years, to be able to tune volume so finely and maintain transparency is greatly valued. 99.5 was perfect for Led Zep, 100 was a bit too loud. Yeah.

The DAC 2.5 employs the Burr-Brown PCM1796 dual-differential multi-bit delta-sigma DAC to perform conversion and upsampling of all inputs to 24-bit/192kHz and has vanishingly low 2 picosecond jitter due to a 2Hz jitter filter feeding a Master Reference Ultra clock. In addition to the usual suspects of input switching and volume control, the DAC 2.5 also offers the ability to control L/R channel balance and absolute phase, even by remote control. The Bel Canto's remote is a simple plastic affair, but it controls almost every function of the 2.5 and works very well. Obviously this is not unique in the audio world or any other planet for that matter, but the ability to control volume, switch phase and correct minor channel imbalances from my chair is very nice indeed.

The dedicated headphone amp is another nice perk. It has its own separately controlled volume so when listening to music through speakers and then connecting headphones, it automatically silences the speakers (and vice versa). While I can only guess that this amp should sound great even with difficult to drive headphones, it forcefully drove my Beyerdynamic DT770 Pro 80 Ohm headphones. The Beyer's are an easy load so it's no surprise that the 2.5 drives the hell out the them with great midrange tone, dazzling highs and rock-solid bass.

For me, the most fascinating choice on the DAC 2.5 is the 24/192kHz ADC analog stereo input. Hook up any stereo analog source with RCA connectors and the Bel Canto will convert the analog signal to digital and upsample it to 24/192kHz with a 110dB dynamic range! Now that is cool. I admit that I could not wait to hear the results after connecting my Music Hall MMF-9/Wright phono stage directly to the 2.5. (Don't be misled, the 2.5's analog input is not a phono stage.) I thoroughly enjoyed listening to a number of great LP's through the Bel Canto. A scratched up copy of George Harrison's All Things Must Pass, The James Gang's Thirds, Al Dimeola's Elegant Gypsy and the Fleet Foxes Helplessness Blues. Most of my vinyl is well used and some don't sound particularly good (most likely damaged during the Haze of Wine and No-Doze's), but LP's that are in quality condition, like my Classic Records re-issue of Led Zep II; sounded really, really, really good. Unfortunately for my record collection, I also take pleasure in the simplicity digital playback affords; especially now that PCM sound quality is rapidly catching up with ease of use. There is no question that a fine analog recording sounds very good through the 2.5 on my system. However, when comparing an average LP played on my analog front end versus a top-notch PCM recording through the 2.5, results return in favor of the zeros and ones…Blasphemous, I know. I also know my audiophool card can be revoked for penning this, but I lost interest in incessantly tweaking some time ago. Oh, and I listen to high-bit rate mp3's, Pandora and MOG on occasion too. I do love gear, but my main goal in audio is to listen to music and now, here comes the ol' Bel Canto DAC 2.5; as close as I have come to having an audiophile "lifestyle" product in house, and dammit, I like it. It is the techno-utility of the 2.5 that really brings it into budget kick-ass territory, but it also sounds damn good... after a while.

One of the most interesting things about audio components is the way they behave brand new out of the box. The notion of "break-in" is a contentious subject and while I have no way to prove such in a scientific manner; I will say that I am in the camp that believes most audio gear changes in sound quality over the course of usage. In my experience, there is no question the DAC 2.5 requires break in to sound its best. At the outset, there was a notable bit of harshness in the upper frequencies which lessened considerably over the first 200 hours of playing time. Eventually the DAC smoothed out and the noisy hash all but disappeared. Even with several hundred hours under the DAC's belt, the sound still seems to be improving. I don't think it's my ears getting any better, but that is subjective. I could be wrong.

So here are my big swing comments about the sound of the 2.5. Aural memory is a fickle beast, but I deem the 2.5 the most resolving digital conversion I have heard in my home system. It is an upfront sound with detail galore and high frequencies that sparkle and light up the listening room. Inner resolution is excellent and the timbre of the instruments is clearly part of the sonic picture. I heard all; hand on hollow-body wood, rosined bow and finger plucks on strings, stick on drum head and the clacking of brass valves—not as a clinical examination of the 3rd Violin's chair scraping the floor—but rather as music. I thought to myself on more than one occasion how I felt the music was telling me a story, a trait which should be at the top of any music lover's list. All this detail and musicality emerge from a quiet backdrop; not quite as black as the battery powered Human Audio Muto perhaps, but the 2.5's built-in LVS power supply is very quiet, fast and dynamic.

Yes, the 2.5 certainly is dynamic, although that may be its least effective attribute. My favorite quality of the DAC 2.5 is its accomplished work as a spatial performer. Sounds come at you from outside, forward and behind the plane of the speakers. With a soundstage so deep and wide, it is a nearly effortless auditory task to discern the influence of venue space on different recordings. Imaging is rock solid and big. There are times when I noted airiness to the music, however this was not always the case and also seemed to be recording dependent. Georgia on My Mind from the First Impression Music Audiophile Reference IV sampler sounded incredible as did my usual audition choices of Sade, Steely Dan, Joe Jackson and Yello. While modern recordings seem to be big and alive in the staging, some older ones, like the Herman's Hermits Retrospective for example, sound closed in and small—just as it was probably recorded. Some older material fared better however, such as the Al Green cut Tired of Being Alone, from his Greatest Hits CD, which sounded absolutely magical as the Al and company all occupied the stage together, music swirling about from one wall to the other and everywhere in between.

Yes, the DAC 2.5 is musical, but it is not rosy. In my system it was simply neutral. Not warm, not clinical, definitely not sterile, seemingly true to the source from start to finish. While not strident, this DAC will not take the edge off of a less than perfect recording and isn't always spit-shine shoe-polish smooth. In fact, I can detect hints of graininess on some recordings. I can also hear similarity to the voicing of my DAC 2, but the level of refinement, transparency, resolution, attack and decay is head and shoulders above the older model 2. Transient response is another great strength of the 2.5. The leading edge is on you in a heartbeat and gives the sonic impression of great speed, adding a stop-on-a-dime quickness to the music that is really nicely done. Treble is extended and mids bloom just enough to keep them beautiful. The bass is deep, tuneful and full of visceral impact.

If you read my take on the Human Audio Muto, you know I think it is an outstanding DAC. It didn't take long to notice at least a couple of major sonic differences between these two performers. The Bel Canto is fiery and alive with a take no prisoners resolution that will tell you if your system is up to snuff, while in comparison, I recall the Muto's relaxed and buttery smooth presentation that was a tone tour-de-force. Yes, the 2.5's revealing nature offers up a little of the ugly once in a while, but it rewards the listener with more of everything, including the good. Especially when using the uLink, you will not wonder if what you are hearing has been tainted by the unit's voicing. Every recording I played sounded distinctly different; from the compression of early 80's pop to the expansive and impactful sound of audiophile jazz and classical recordings. It took me a while, but I finally put my finger on one key attribute of the Bel Canto: It digs deep into the music, reconstructing a sometimes brightly lit and always transparent sonic picture. Being a guy who likes a bit of warm/dark, this occasionally challenged me. Sometimes the truth hurts. However, as it is said, the truth will also set you free. And while the 2.5 can at times challenge my idea of how I want my music to sound, there is no question that it sounds great doing so.

USB vs. USB

The 2.5's own USB Link input is very good. Its driverless interface makes connection as simple as plugging in. Since most of my music files are 16-bit/44.1 kHz, I could easily live with this as my only USB connection. But here is the rub: Bel Canto sent me their new uLink. The ulink has a single USB input and a choice of S/PDIF RCA or ST Fiber output (The DAC3.5 has an ST input). I gotta admit, it is hard to tell the two converters apart in a quick A/B test, but over time (and not a lot of time either), it was obvious the uLink adds an additional level of sophistication and a more analog flavor to the digital signal. If the main job of a USB converter is to feed a DAC the cleanest digital signal possible from the computer; smoothing out the digital potholes and isolating the signal from digital switching noise and power line gunk, then the uLink is a winner hands down. High quality audio playback via USB is still relatively new to me and while I was fairly certain I would find the uLink superior to the 2.5's internal USB, I was not prepared for the improvement uLink made in the sound of my own Bel Canto DAC 2. Like its newer relative, the DAC 2 upsamples to 24/192kHz and while there are some sonic similarities, the DAC 2 seems a tad warmer and less incisive than its big brother. But feeding that old 2 from the uLink and its sound rating climbed at least one notch higher on the "obviously better" scale and showing the DAC 2 is still a solid performer after all these years.

bel canto ulink

Preamp or no preamp, that is the question...

It took much longer than anticipated for the Bel Canto DAC 2.5 to settle in, but once there, it didn't disappoint. I determined over time that using the DAC 2.5 as a preamp to directly drive my single-ended 845 amplifier was not the only choice for my system. The Audiotropic Moebius gave the sound a big and wonderful tube perspective, but in the end I preferred the Slagle AVC with its combination of high resolution and low noise, even as I gave up a bit of bass slam and the huge, dynamic staging of the active pre. The Bel Canto as a preamp did sound excellent and I used it this way for many hours—I just happen to like the sound of the AVC better. I did try the AVC with the 2.5's volume output in the fixed position, but went back to variable output solely because I could tweak the volume of the stepped AVC more to my liking. Yes I know, that is offensive audiophile behavior. I am a bad, bad, man—but my volume is perfect.

The Sum and Totals

The DAC market is crowded with a seemingly endless stream of new products and a lot of them are undoubtedly very good as is the DAC 2.5. The $2k Bel Canto is an excellent PCM digital audio converter, and while not exactly cheap as a standalone DAC, when factoring in the functionality it offers it would be hard to give the DAC 2.5 less than a value high-five. So I am. For the listener who requires truthfulness and very high resolution, this unit is a must audition. If you have a little bigger pile of cash, add the uLink USB converter and you'll have a killer digital front-end that will stand the test of time. Highly recommended.

www.belcantodesign.com

Bel Canto DAC 2.5 Control Center:   
Retail $1995

Bel Canto uLink USB Link Converter
Retail $675

 

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